Artificial heart valve



Aug. 13, 1968 D. G. MELROSE ARTIFICIAL HEART VALVE 2 Sheets-Sheet 1 Filed Dec.

s- 3, 1968 D. G. MELROSE 3,396,409

ARTIFIC IAL HEART VALVE v Filed Dec. 9, 1965 2 Sheets-Sheet United States Patent 0 3,396,409 ARTIFICIAL HEART VALVE Denis Graham Melrose, London, England, assignor to National Research Development Corporation, London, England, a British company Filed Dec. 9, 1965, Ser. No. 512,65 Claims priority, application Great Britain, Dec. 31, 1964, 53,104/64 12 Claims. (Cl. 3-1) This invention relates to an improved form of a oneway valve suitable for use as an artificial heart valve in surgical heart prosthesis.

Mitral valve deficiency is one characteristic of congenital or acquired heart disorders, such deficiency being manifest in the inability of the valve to operate strictly as a one-way valve which is its normal and essential function. In such a case therefore it is necessary to replace the deficient valve with an artificial one-way valve. Examples of heart valve incompetence are known, where the natural valve system operates in such a restricted environment that artificial heart valves hitherto available may not be successfully used as a replacement.

According to the invention there is provided a one-way fluid control valve adapted for actuation by a reversal of fluid flow which comprises, a lenticular-shaped valve closure member having at least two well-spaced tapering guide members projecting from one of its faces, at least one guide member projecting further than another, and a ring-member which surrounds at least part of said guide members the surface of the ring-member adjacent said one face of the closure member being adapted for engagement with a seating portion of said face so as, in operation, to effect closure of the valve, said guide members being so shaped as to provide by abutment with said ring-member limitation of movement of said closure member away from said seating portion of said ring member.

To restrict rotation of the valve closure member relative to the ring-member stop means are provided on the ring-member for engagement with said guide members.

According to one embodiment of the invention said stop means is formed by a recession of the inward facing surface of the ring-member, said longer guide members b ing located by said recess.

According to another embodiment of the invention, said stop means comprises an abutment positioned on the inward facing surface of said ring-member, the abutment be ing located between two of said guide members.

In surgical prosthesis such an implanted member is initially sutured to the surrounding living tissue but it is preferable to take advantage of the natural fibrosis which can occur between living tissue and a porous material. The ring-member by which location of the valve in a valve orifice is effected therefore has the outward facing surface thereof channelled in which channelled surface a biologically inert porous material is positioned. The heart tissue surrounding the artificial valve grows by fibrosis into the porous material thereby securing the ring-member in the valve orifice.

The shaping of the aforesaid guide members for abutment with the channelled ring-member will be governed by any restrictions imposed by the structure of the heart surrounding the inlet side of the valve. The guide members therefore may, for a restricted environment, be of rod like form of minimum length and having their free ends shaped to abut the ring-member. Where the environment imposes no such restrictions the guide members may be of arcuate form, the concave side of which members being adjacent the ring-member, the concavity and length of which members being dictated by their position on the 3,396AW Patented Aug. 1 3, 1968 surface of the closure member and therefore the function which the member has to perform.

The valve closure member is preferably though not essentially comprised of a rigid material, although it will be apparent that for a reliable valve seal, by the engagement of one face of the closure member with a seating surface of the channelled ring member, at least one of these two members must be of substantially rigid form. It is therefore preferable that the means for securing the valve in the valve orifice is of a substantially rigid form. The word lenticular is used to describe the shape of the valve member indicates that the member has the shape of a bi-convex lens and which preferably has the cross-section of that of a spherical bi-convex lens; the perimeter of the member however need not necessarily be circular.

The choice of materials from which the valve components may be prepared is governed by two requirements. The first and most important requirement being that the material must essentially be of a biologically inert nature; the second requirement is that the material must be capable of being worked or moulded to produce the required shapes of the valve components and must in certain instances be capable of being produced in a substantially rigid form. Examples of such materials suitable for the components of the valve are the metals, stainless steel, platinum and titanium and the synthetic materials, polypropylene, polyvinyl alcohol, polytetrafiuoroethylene and polystyrene.

In a further embodiment of the invetnion therefore the means positioned in the channel of the ringmember to secure the ring-member to the surrounding heart tissue may comprise a stainless steel ring encased in a biologically inert porous sponge material.

In a further embodiment of the invention said securing means comprises a polytetrafiuoroethylene ring encased in a biologically inert porous sponge material. In a preferred embodiment of the invetnion said biologically inert porous sponge material comprises polypropylene mesh.

One example of an artificial heart valve in accordance with the invention will now be described with reference to the accompanying drawings in which FIGURES 1, 2, 4 and 5 show side elevations in section of two alternative forms of an artificial mitral valve in the closed and open position respectively, and FIGURES 3 and 6 show perspective views respectively of such valves.

In FIGURES 1, 2 and 3 there is shown a one-way artificial heart valve which comprises a substantially rigid ring-member 1 having a lenticular-shaped valve closure member 2 positioned below the ring-member 1. An annular seating surface 3 is positioned on the lower and inward facing surface of the ring member 1 against which the upper surface 4 of the closure member 2 contacts to effect a fluid tight seal on valve closure. Guide members 5 and 6 are positioned on the upper surface of the closure member 2 and depend freely through the ring member 1 and are shaped at their upper ends to abut the ringmember 1 to limit downward movement of the valve closure member 2. Guide member 5 is substantially longer than guide member 6 in order that the valve closure member 2 with the valve in the fully open position can assume the asymmetrical position as shown. A stainless steel ring is located in a groove 8 on the periphery of the ring member 1 and is itself encased in a biologically inert porous material 9 which porous material 9 engages with the surrounding tissues when inserted in a heart valve orifice and enables fibrosis to occur between the tissue and the porous material. A recession It) on the inward facing surface of the ring-member is provided for receiving guide member 5 to restrict rotation of the valve closure member 2 relative to said ring member.

In FIGURES 4, 5 and 6 there is shown a one-way artificial heart valve which comprises a substantially rigid ring-member 11 having a lenticular-shaped valve closure member 12 positioned below the ring-member 11. An annular seating surface 13 is positioned on the lower and inward facing surface of the ring-member 11 against which the upper surface 14 of the closure member 12 contacts to effect a fluid tight seal on valve closure. Guide members 15 and 16 are positioned on the upper surface of the closure member 12 and depend freely through the ringmember 11 and are shaped at their upper ends to abut the ring-member 11 to limit downward movement of the valve closure member 12. Guide member 15 is substantially shorter than guide members 16 in order that the valve closure member 12 with the valve in the fully open position can assume the asymmetrical position as shown. A polytetrafluorethylene ring 17 is located in a groove 18 on the periphery of the ring-member 11 and is itself encased in a. biologically inert porous material 19 which porous material 19 engages with the surrounding tissues when inserted in a heart valve orifice and enables fibrosis to occur between the tissue and the porous material. An abutment 20 is positioned on the inward facing surface of the ring-member between two of the guide members 16 to restrict rotation of the valve closure member 12 relative to said ring-member.

It will be apparent from the construction of the artificial heart valve in accordance with the invention that the valve will in operation have an opening action directing the fiow of blood into an area where the flow is most required or at least most able to accommodate it. Furthermore it will be seen that although the positioning of the guide members is arranged primarily to produce a flow directing effect their positioning and shape is also effective in producng maximum scouring action by the blood flow in passage through the valve, thereby serving to minimize blood clot formation on the surfaces of the valve members.

I claim:

1. A one-way fluid control valve adapted for actuation by a reversal of fluid flow which comprises, a lenticularshaped valve closure member having at least two welltapering guide members projecting outwardly from one of its faces, at least one guide member projecting further than another, and a ring-member which surrounds at least part of said guide members the surface of the ring-member adjacent said one face of the closure member being adapted for engagement with a seating portion of said face so as, in operation, to effect closure of the valve, said guide members being so shaped as to provide by abutment with said ring-member limitation of movement of said closure member away from said seating portion of said ring-member.

2. A one-way valve according to claim 1, wherein stop means is provided for restricting rotation of said closure member relative to said ring-member.

3. A one-way valve according to claim 2, wherein said stop means is formed by a recession of the inward facing surface of said ring-member, at least one of said longer guide members being located by said recess.

4. A one-way valve according to claim 2, wherein said stop means comprises an abutment positioned on the inward facing surface of said ring-member, said abutment being located between said guide members.

5. A one-way artificial heart valve according to claim 2, wherein the outward facing surface of said ring-member is channelled.

6. A one-way artificial heart valve according to claim 5, wherein there is positioned in the channel of said ringmember securing means for effecting location and securement of said ring-member in a heart valve orifice.

7. A one-way artificial heart valve according to claim 6, wherein said securing means comprises a stainless steel ring encased in a biologically inert porous sponge material.

8. A one-way artificial heart valve according to claim 6, wherein said securing means comprises a polytetrafiuoroethylene ring encased in a biologically inert porous sponge material.

9. A one-way artificial heart valve according to claim 8, wherein said biologically inert porous sponge material is comprised of a polypyropylene mesh.

10. A one-way artificial heart valve according to claim 9, wherein the valve closure member, guide members and channelled ring-member are comprised of polypropylene.

11. A one-way artificial heart valve adapted for actuation by a reversal of blood-flow which comprises, a lenticular-shaped valve closure member having three wellspaced tapering guide members projecting outwardly from one of its faces one of said guide members. projecting further than said other two guide members, a ring-member which surrounds at least part of said three guide members, the surface of the ring-member adjacent said one face of the closure member being adapted for engagement with a seating portion of said face so as, in operation, to effect closure of the valve, said guide members being so shaped as to provide by abutment with said ring-member limitation of movement of said closure member away from said seating portion of said ring-member, a channel-shaped housing formed in the outward facing surface of said ringmember and having located therein a polytetrafluoroethylene ring encased in polypropylene mesh, and stop means for restricting rotation of said closure member relative to said ring-member formed by a recession of the inward facing surface of said ring member said longer guide member being located by said recess.

12. A one-way artificial heart valve adapted for actuation by a reversal of blood-flow which comprises, a lenticular-shaped valve closure member having three wellspaced tapering guide members projecting outwardly from one of its faces, two of said guide members projecting further than said other one guide member, a ring-member which surrounds at least part of said three guide members, the surface of the ring member adjacent said one face of the closure member being adapted for engagement with a seating portion of said face so as, in operation, to elfect closure of the valve, said guide members being so shaped as to provide by abutment with said ring-member limitation of movement of said closure member away from said seating portion of said ring member, a channel-shaped housing formed in the outward facing surface of said ring-member and having located therein a polytetrafluoroethylene ring encased in polypropylene mesh, and stop means for restricting rotation of said closure member relative to said ring-member, comprising an abutment positioned on the inward facing surface of said ring-member, said abutment being located between said two long guide members.

References Cited UNITED STATES PATENTS 2,564,023 8/1951 Miller 137533.17 3,294,116 12/1966 Tremeau 137-533 XR OTHER REFERENCES Prosthetic Replacement of the Mitral Valve, The Lancet, Nov. 24, 1962, p. 1087.

Pioneer Invents New Heart Valve, by Nate Haseltine, in The Washington Post, Nov. 24, 1963.

Evaluation of Two Prostheses for Total Replacement of the Mitral Valve, by F. S. Cross et al., The Journal of Thoracic and Cardiovascular Surgery, vol. 46, No. 6, December 1963, pp. 719-725.

RICHARD A. GAUDET, Primary Examiner.

R. L. FRINKS, Assistant Examiner. 

1. A ONE-WAY FLUID CONTROL VALVE ADAPTED FOR ACTUATION BY A REVERSAL OF FLUID WHICH COMPRISES, A LENTICULARSHAPED VALVE CLOSURE MEMBER HAVING AT LEAST TWO WELLTAPERING GUIDE MEMBERS PROJECTING OUTWARDLY FROM ONE OF ITS FACES, AT LEAST ONE GUIDE MEMBER PROJECTING FURTHER THAN ANOTHER, AND A RING-MEMBER WHICH SURROUNDS AT LEAST PART OF SAID GUIDE MEMBERS THE SURFACE OF THE RING-MEMBER ADJACENT SAID ONE FACE OF THE CLOSURE MEMBER BEING ADAPTED FOR ENGAGEMENT WITH A SEATING PORTION OF SAID FACE SO AS, IN OPERATION, TO EFFECT CLOSURE OF THE VALVE, SAID GUIDE MEMBERS BEING SO SHAPED AS TO PROVIDE BY ABUTMENT WITH SAID RING-MEMBER LIMITATION OF MOVEMENT OF SAID CLOSURE MEMBER AWAY FROM SAID SETTING PORTION OF SAID RING-MEMBER. 